Project获取资源需要一个启点，加载资源的动作是由ClassLoader来完成的。Class对象和当前线程对象可以找到当前加载资源的ClassLoader，通过ClassLoader的getResource(String name)方法及其它衍生出来的方法可以找到Application的启点及获取相关资源

private void display() {path=this.getClass().getResource("/loadresource").getPath();System.out.println(path);path=this.getClass().getResource("/loadresource/bp.txt").getPath();System.out.println(path);path=this.getClass().getResource("/").getPath();System.out.println(path);URL url=this.getClass().getResource("loadresource/bp.txt");System.out.println("Is Null:"+(url==null));path=GetResouceTest.class.getClassLoader().getResource("").getPath();System.out.println(path);path=GetResouceTest.class.getClassLoader().getResource("loadresource/bp.txt").getPath();System.out.println(path);url=GetResouceTest.class.getClassLoader().getResource("/loadresource/bp.txt");System.out.println("Is Null:"+(url==null));path=Thread.currentThread().getContextClassLoader().getResource("").getPath();System.out.println(path);path=Thread.currentThread().getContextClassLoader().getResource("loadresource/bp.txt").getPath();System.out.println(path);url=Thread.currentThread().getContextClassLoader().getResource("loadresource/bp.txt");System.out.println("Is Null:"+(url==null));url=Thread.currentThread().getContextClassLoader().getResource("/loadresource/bp.txt");System.out.println("Is Null:"+(url==null));}

/E:/java/workspace/test/bin/loadresource
/E:/java/workspace/test/bin/loadresource/bp.txt
/E:/java/workspace/test/bin/
Is Null:true
/E:/java/workspace/test/bin/
/E:/java/workspace/test/bin/loadresource/bp.txt
Is Null:true
/E:/java/workspace/test/bin/
/E:/java/workspace/test/bin/loadresource/bp.txt
Is Null:false
Is Null:true

 /*** Finds a resource with a given name.  The rules for searching resources* associated with a given class are implemented by the defining* {@linkplain ClassLoader class loader} of the class.  This method* delegates to this object's class loader.  If this object was loaded by* the bootstrap class loader, the method delegates to {@link* ClassLoader#getSystemResource}.** <p> Before delegation, an absolute resource name is constructed from the* given resource name using this algorithm:** <ul>** <li> If the {@code name} begins with a {@code '/'}* (<tt>'\u002f'</tt>), then the absolute name of the resource is the* portion of the {@code name} following the {@code '/'}.** <li> Otherwise, the absolute name is of the following form:** <blockquote>*   {@code modified_package_name/name}* </blockquote>** <p> Where the {@code modified_package_name} is the package name of this* object with {@code '/'} substituted for {@code '.'}* (<tt>'\u002e'</tt>).** </ul>** @param  name name of the desired resource* @return      A  {@link java.net.URL} object or {@code null} if no*              resource with this name is found* @since  JDK1.1*/public java.net.URL getResource(String name) {name = resolveName(name);ClassLoader cl = getClassLoader0();if (cl==null) {// A system class.return ClassLoader.getSystemResource(name);}return cl.getResource(name);}

   /*** Add a package name prefix if the name is not absolute Remove leading "/"* if name is absolute*/private String resolveName(String name) {if (name == null) {return name;}if (!name.startsWith("/")) {Class<?> c = this;while (c.isArray()) {c = c.getComponentType();}String baseName = c.getName();int index = baseName.lastIndexOf('.');if (index != -1) {name = baseName.substring(0, index).replace('.', '/')+"/"+name;}} else {name = name.substring(1);
        }return name;}